Electrical termination



United States Patent ELECTRICAL TERMINATION George C. Mapelsden, Easton,and Francis H. Cowe, Devon, Conn, assignors to General Electric Company,a corporation of New York t 1 Filed Apr. 1, 1957, Ser.No. 649,688 3Claims. or. 339-276) This invention relates to a means of crimping awire conductor to an electrical contact or terminal. Portable electricalcords usually are provided with attachment plugs with two or morecontacts or blades which are inserted into a convenience outlet formaking an electrical connection. In some attachment plugs the contactsextend in a direction longitudinally of the cord, while in others thecontacts are perpendicular to the cord. Such plugs in the lattercategory are oftentimes referred to as right angle plugs or merely asangle plugs.

The present invention finds its greatest use in angle plugs where thestranded wire is crimped to the contacts with a right angle crimp. Thisangular relation between the wire and the contact has fostered the useof the designation flag-type crimp for reasons which will be immediatelyapparent after studying the article in question. Previously, the wireconductors were fastened to the contacts of an angle plug in the samemanner as in standard plugs so that the contacts were mere extensions ofthe conductors. However, this became very troublesome with the largersize conductors since the copper strands would oftentimes break when theconductors were bent at such a sharp angle before the plugs could bemolded. This bending operation both stretches the outer strands of theconductors and work-hardens the material so that breakage may occureither in handling or during the molding operation. substitute aflag-type crimp so that little or no bending will be required inassembling the contacts in the mold ing machine.

The principal object of this invention is to provide an electricalconnector with a flag-type. crimp having a special latching featurewhich will resist the loosening of the gripping force when the wireconductor is under tension.

A further object of this invention is to provide a flag-type crimp forthe contacts of an angle plug having a special latching arrangement thatwill hold the crimped portion firmly in engagement with the wire andwill not tend to shear the strands of the wire.

The preferred embodiment of this invention is illustrated in the drawingas it would be incorporated with the contact blade of an angle plug. Thesame invention would also be useful as a connection between a wire and aterminal member; or wherever a wire, be it solid or stranded, is to beconnected to a thin strip of metal. A slotted opening is first formedadjacent one end of the strip and then a tab is lanced out of the stripto serve later as the latching member. In actual practice, the tab isformed from material adjacent the opening so that when it is folded backit enlarges the opening. The adjacent end of the strip containing theslottedopening is likewise preformed outwardly to lie parallel with thebeforementioned tab to form a receiving section for a wire conductor.Such a conductor is placed crosswise of the opening and the end of thestrip is rolled over the conductor to produce a tight grip. Finally, thetab is Our solution is to 2,947,968 Patented Aug. 2, 1960 room airconditioners.

Our invention will be better understood from the following descriptiontaken in connection with the accompanying drawing and its scope will bepointed out in the appended claims. 7

Figure 1 is a plan view of an electrical contact embodying our inventiontaken before the crimping operation.

Figure 2 is a right end view of the contact of Figure 1 showing theterminal end.

Figure 3 is a side elevational view of the contact of Figure 1.

Figure 4 is a partial view showing a blank of the material from whichthe contact is formed.

Figure 5 is an isometric view of the contact embodying our inventionbefore the crimping operation takes place.

Figure 6 is an isometric view similar to that of Figure 5 with the wirecrimped firmly to the contact.

Referring in detail to the drawing and in particular to Figure 5, 10represents an electrical contact of thin metal strip material which isdoubled over to form a two-ply blade construction with a short leg 11and a long leg 12. The folded end of the contact has an anchor loop 13for making good mechanical connection with the contacts (not shown) of aconvenience outlet. A circular aperture 14 through the contact adjacentthe anchor loop 13 is also provided for increasing the mechanicalholding force between the contact and a receptacle. The free end 15 ofthe short leg 11 is bent outwardly at a right angle to the main portionof the contact so that when a plug is molded over the end of thecontact, the portion 15 will serve to anchor the contact and preventdisplacement and withdrawal.

The novel portion of our invention may be seen at the free or terminalend 16 of the long leg 12 of the contact. A slotted opening 17 is madein the terminal end, and a tab 18 is lanced out of the material formingone edge of the opening. This opening 17 is spaced from the edges ofterminal end 16, with a transverse rib spacing it from the outertransverse edge of the terminal end 16. (See Fig. 5.) This tab 18 isbent at a right angle, and in so doing the slotted opening 17 isenlarged to the dimensions as shown. Figure 4 shows a blank of theportion of the long leg 12 of the contact where the tab 18 is situatedin the plane of the leg. It should be understood, however, that the tab18 is not cut as shown in Figure 4 and then folded, but that it islanced or struck out of the material of the contact in one operation.

Looking at Figure 3, the terminal end 16 is made with a partial loop 20that is open upwardly and an upstanding portion that lies parallel withthe lanced tab 18. This is the condition of the contact just prior tothe assembly of the wire conductor 21 of Figure 6. The conductor isplaced in the loop portion 20 across the slotted opening 17 and betweenthe terminal end 16 and the tab 18. Then the terminal end 16 is rolledover the conductor so that the free edge of the terminal end 16 liesadjacent the base of the tab 18. This type of connection would besatisfactory in many situations, but the tab 18 is an additionalprecaution that will prevent the terminal end 16 from springing back andreleasing its grip onpthe conductor. Tab 18 is formed over the terminalend where it latches into the slotted opening 17 as shown in Figure 6.The tab 18 is not actually crimped over the conductor, but it is crimpedover the terminal end of the contact.

Having described above our invention of a novel flagtype crimp for anelectrical connector, it should be clear to those skilled in this artthat the resulting product is both simple to manufacture and reliable inoperation. It is'so designed that it is well adapted to mass productionmethods of stamping by progressive dies, and it represents a decidedimprovement in angle plugs over previous methods of crimping thevcontacts where the contacts extended longitudinally of the conductors.

Modifications of our invention will occur to those skilled in this art,and it is; to be understood, therefore, that; this invention is not.limited, to the particular embodiments disclosed, but that it isintended to cover all modifications which are within the true spirit andscope of thisv inventon.

What we claim is new and desire to secure by Letters Patent of theUnited, States is:

1. An electrical connector of thin metal strip having a terminal endthat is to be crimped over a bare conductor, a lanced tab struck out ofone side of the terminal end of said stirp to establish an opening inthe end that is spaced from the edges of the strip, a bare wire lyingacross the terminal end and over the opening, the terminal end beingrolled over the wire on said side of said strip to hold the wire firmlyin place, the tab also being rolled over the crimped portion of theterminal end to WIIG.

2. An electrical connector of thin metal strip of doubled=overconstruction comprising a long and a short leg, the free end of the longleg having a slotted opening that is spaced from the edges of the strip,said opening being spaced from the outer transverse edge of the free endby a transverse rib, a lanced tab struck from said strip and projectingoutwardly from one side of said strip, a wire conductor extending acrosssaid strip and lying over said opening, said free end of said stripbeing folded over said conductor with the transverse rib of said stripadjacent said side of said strip, said tab formed over the free end andlatched into the opening to engage said rib and hold the free end of thestrip from releasing its grip on the conductor.

3. An electrical connector of thin metal material comprising a slottedopening adjacent one end, said opening spaced from the outer transverseedge of said end by a transverse rib, a wire conductor lying across theend of the connector and over the opening, said end of the materialbeing folded over the conductor to hold it in a tight grip, saidtransverse rib disposed on one side of said strip, and a tab extendingoutwardly from said side of said strip and folded over said rib andlatched into the opening to hold the end from releasing its grip on theconductor.

References Cited in the-file of this patent UNITED STATES PATENTS445,491 Biesen Jan. 27, 1891 2,445,537 Schaefier July 20, 1948 2,659,871Berg Nov. 17, 1953 2,765,454 Long Oct. 2, 1956 2,845,108 Hammell et a1.July 29, 1958

